Method of making composite car-wheels



{N5 Model) N. WASHBURN.

METHOD OF MAKING COMPOSITE GAR WHEELS.

No. 522,633. Patented July 10,1894.

INVENTE] R THE scams mans ca. PuoToLm-m, WASHINQTON. n. c.

, UNITED STATES] PATENT OFFIC NATHAN WASIHBURNyOF BoSTo'N, MASSACHUSETTS.

METHOD, OF MAKING COMPOSITE CAFl WHEELS.

SPECIFICATION forming part Of Letters Patent No. 522,633, dated T 10, 1894. Original application filed January 28, 1893, Serial No. 460,033. Divided and thisapplication filed October 14,1893. Serial No.

488,148. No specimens.)

To all whom it may concern.- 7

Be it known that I, NATHAN WASHBURN,

residing in Boston, in the county of Suffolk \and State of Massachusetts, have invented'an Improvement in Methods of Making Compo:

site Oar-Wheels, of which the following .description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts. This application is a division of another application, Serial No.,46'0,033, filed by me Jannary 28, 1893, and relates to a novel method for the production of the composite car wheel consisting of a cast-iron center or body and a chilled rim or tread converted into steel,

of the chilled portion, when fractnred,shows a laminated structure, the laminations of which are extended toward the center or hub of the wheel, whichis due to the fact, that a portion of the carbon originally in the tread 2 5 or rim is driven out'ofthe chilled portion into the body or center of the wheel by the chilling process, thereby leaving the chilled portion composed of what is known as white metal-or white cast-iron. The chilled portion of the rim or tread has imparted to it, by

the chilling process, great hardness but at a sacrifice to its strength. By experiment, I have ascertained that the chilled portion of the rim .or tread of the car-wheel may be changed and converted into"'steel, and have its physical'structure changed from a brittle, laminated structure to a very tough and tenacious, fibrous structure, capable of being turned and drilled, by subjecting the wheel 40 to the action of a decarbonizing flame produced by the combustion of a hydro-carbon, preferably crude petroleum oil, and at the same time, the center 'or body of the wheel of cast-iron is greatly improved in strength.

My invention therefore consists in the method of manufacturing acomposite carwheel composed of a cast-iron center or body and a chilled rim or tread integral therewith and converted into steel, which consists in 5 subjecting a cast-iron wheel having a chilled rim or .tread to the direct action of a flame produced by the combustion of a hydrocarbon.

Figure 1, is a diametrical section of a por tion of a car-wheel representing a cast-iron wheel having a chilled rim or tread, substantially such as now commonly made, and Fig. 2, a diametrical section of a portion of a carwheel having a cast-iron center and a chilled rim or tread integral therewith and converted into steel, and which represents the wheel shown in Fig. 1, after treatment by the process hereinafter described.

Referring to Fig. 1, A represents the center or body of acast-iron wheel, which may be of any usual or WOlI'kHOWH construction and which is provided with a chilled rim or tread a, the chilled portion of the rim or tread being represented by the lines radiating toward the center of the wheel to represent laminations ofv the chilled metal.

In accordance with my'invention, the castiron wheel represented in Fig. l, is converted into a composite Wheel, in which the component parts are integral-with each other, by subjecting the same in a suitable furnace or apparatus, not herein shown, to the direct action of a decarbonizing flame, produced by the combustion of a hydro-carbon, preferably crude petroleum oil, the said wheel being al-' lowed to remain in the furnace and exposed to'the direct action of the products of combustion of the crude petroleum oil, until the chilled portion of the wheel, shown in Fig. 1, has been converted into steel which, in practice, I have effected in about three or four hours. During the time in which the castiron car-wheel having a chilled rim or tread is'subjected to the flame arising from the burning oil, the chilled portion of the tread is decarbonized and gradually changed from cast-iron into steel, and its laminated structure, represented in Fig. l, is entirely changed cast-iron wheel a sufficient length of time to 9 5 convert the chilled portion of the wheel into steel, the'wheel is allowed to cool gradually, which may be eifected by withdrawing the heat from the furnace or apparatus in which the wheel is converted, or in any other desired manner. \Vhen the conversion has been completed, the Wheel, thus produced, consists of a cast-iron body or center and a steel rim or tread integral therewith, which possesses all the properties of a car-wheel having a cast-iron center and a hammered and rolled steel tire bolted thereto.

lhe composite car-wheel, thus made, owing to the cheapness of the cast-iron and to the substantially small cost of converting the chilled portion of the wheel into a steely metal, may be produced at a substantially small cost, and can be used equally well for freight or passenger service, and it is more especially advantageous, owing to the fact, that it can be used on freight service without any material additional cost over the common cast-iron car-wheel having a chilled rim or tread, now commonly used.

In freight service, car-Wheels composed entirely of steel or of cast-iron having a hammered and rolled steel tire, are prohibited from use by their cost, whereas the composite wheel herein described, may be used on freight cars and thereby avoid the accidents occasioned by broken cast-iron car-wheels.

I am aware that chilled cast-iron wheels have been subjected in a furnace to the action of a flame produced by the combustion of coal, charcoal, and like bodies, and have been heated in said furnace for four days and longer, for the purpose of relieving the metal from strain and preventing the splitting or tearing apart of the metal due to uneven cooling of the same. In this process, the chilled portion of the rim is unaffected by the flame,

and after treatment, the chilled portion is the same as before treatment and remains chilled cast-iron.

By my process herein described, the flame produced by the combustion of ahydrocarbon, such as crude petroleum oil, has a decarbon izing effect on the chilled portion, as I am led to believe not only by the physical properties of the metal produced, but also by analysis, which shows a reduction in the amount of carbon in the chilled portion after treatment.

I claim- 1. The method of manufacturing a composite car-wheel composed of a cast-iron center or body and a chilled rim or tread integral therewith and converted into steel, which consists in subjecting a cast-iron Wheel having a chilled rim or tread to the direct action of a flame produced by the combustion of a hydrocarbon, substantially as described.

2. The method of manufacturing a composite car-Wheel composed of a cast-iron center or body and a chilled rim or tread integral therewith and converted into steel, which consists in subjecting a cast-iron wheel having a chilled rim or tread to the action of the products of combustion of crude petroleum oil, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribiu g Witnesses.

NATHAN W'ASI] BURN.

Witnesses:

J AS. l-I. CHURCHILL, J. MURPHY. 

